We report 0.8 - 2.5 micron spectroscopy of Nova Ophiuchi 1998 using the Aerospace near infrared imaging spectrograph and the 3 meter Shane telescope at Lick Observatory on June 19.40, on June 21.37 UT and October 2.15 1998 UT. On the first night the Paschen and Brackett emission lines dominated the spectrum, although HeI 1.0830 microns was the strongest single line present and HeII was very weak. There was also an unusual continuum emission feature present between 1.07 and 1.10 microns that was about twice the heigth of the surrounding continuum. Three nights later the nova’s rapid evolution to higher excitation conditions was evident from the much stronger HeII lines which had increased by a factor of 4 relative to the hydrogen lines. The CIII line at 0.9710 microns also appeared the second night, a line that we have heretofore seen only in Wolf-Rayet stars and which almost certainly indicates an overabundance of carbon. The strange continuum feature was also present. About 100 days later on October 2.15 UT, the emission lines were very weak (5-15 only a few Paschen features and lines of HeII were present. The unusual continuum feature was absent. In both June and October the continua, though somewhat different in shape, were blue and resembled a stellar continuum. There was no evidence of a long wavelength upturn indicative of thermal emission from dust. The June and October the continuum magnitude at J (1.25 microns) were 9.4, 10.9 to 15.0, respectively.
American Astronomical Society Meeting Abstracts #193
- Pub Date:
- January 1999